Debt - Total Amount of Interest Expense and Fees Recognized on Borrowing under New Credit Agreement (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Debt Disclosure [Abstract]
Interest expense and fees	$ 3,761	$ 3,424	$ 3,303